1. Field of the Invention
This invention relates to a method for forming a via contact hole in a semiconductor device, more particularly to a method for removing the residual of a photoresist layer and a polymer layer after the etching process used for forming the via contact hole is completed.
2. Information Disclosure Statement
As is generally known, in the process of forming a via contact hole in a semiconductor device, it is very important to remove the residual of a polymer layer formed at the via contact hole during the etching process. Moreover, since the manufacturing process of a highly integrated semiconductor device requires equipment having various structures, it is difficult to perform the above mentioned process used for removing the residual of the polymer layer.
In the manufacturing process for forming the via contact hole of a semiconductor device, after the via contact hole is formed by the etching process, first, a photoresist layer is removed using O.sub.2 plasma stripper and, second, the polymer layer is removed using deionized water and stripper solution. In such a case, as in the case of overetching the via contact hole, most etching processes for forming the via contact hole etches a part of the metal layer beneath a SiO.sub.2 layer as well as the SiO.sub.2 layer. Therefore, the polymer layer produced by the reaction of the photoresist layer, the SiO.sub.2 layer and metal layer is formed on the sidewall of the photoresist layer on the SiO.sub.2 layer associated with the via contact hole.
When the photoresist layer is removed using O.sub.2 plasma stripper, the above polymer layer is transformed and hardened so that it is not easily removed by the next process for removing the polymer layer. In order to remove the polymer layer, an etchant which may etch the metal layer or a strong stripper solution is used. However, the problem is that the short of the via contact hole results by etching a part of the metal layer as well as the polymer layer.